Divisibility Rules

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Transcript Divisibility Rules

Divisibility Rules
How do we know when we can
divide one number into another
exactly?
Jenny Russell
Divisibility Rules (2)
 A number can be
divided by 2 if
 the last digit is even
Divisibility Rules (3)
 a number is divisible
by 3 if
 the sum of the digits is
divisible by 3
Divisibility Rules (4)
 a number is divisible
by 4 if
 the number made by
the last two digits can
be divided by 4
Divisibility Rules (5)
 A number is divisible
by 5 if
 the last digit is a 5 or a
0
Divisibility Rules (6)
 A number can be
divided by 6 if
 It passes the rules for 2
and 3.
Divisibility Rules (9)
 A number is divisible
by 9 if
 the sum of all the
digits is divisible by 9.
Divisibility Rules (10)
 A number can be
divided by 10 if
 the last digit is a 0
Divisibility Rules
 2, the last digit will be an even number
 3, the sum of all the digits is divisible by 3.
 4, the number made by the last two digits
can be divided by 4
 5, the last digit will be a 5 or 0
Divisibility Rules
 6, if it passes the rules for 2 and 3.
 9, the sum of all the digits is divisible by 9.
 10, the last digit will be a 0.
Divisibility Rules
 There is no easy test for 7 and 8 although
some methods have been invented, however
it is easier to use a pencil and paper method.
Divisibility Rules
 Apply these rules to these numbers:
 74,673,042
 444,555,448
 61,616,168
 732,510
 66,666,666
 179,131,590